The invention relates to a device for displaying the active state of a braking system in motor vehicles.
Thus far it has been known to control a known pilot light for indicating defects in a pulsed manner to display the active state of a braking system in motor vehicles, especially an anti-lock braking system (ABS) and/or an acceleration spin control system (ASC) with braking intervention. However, a flashing pilot light used to display the active state of the braking system can lead the driver to suspect incorrectly that there is a defect in the braking system.
It is also known that the active state of a braking system can be detected by the driver haptically, especially in the form of vibrations at the brake pedal. However, this haptic signal will be absent in future braking systems that are controlled purely electronically. If there is no indication whatsoever of the active state of the braking system, the driver could gain the impression, especially at very low coefficients of friction, that the action of the brakes is insufficient.
There is therefore needed an improved device of the above-mentioned type such that the driver firstly is not irritated and secondly is sufficiently informed about the braking process influenced by the braking system.
These needs are met according to the present invention by a device for displaying the active state of a braking system in motor vehicles. A display compares a value proportional to the maximum possible braking force with a value proportional to the actual braking force. The display is provided in the driver""s field of vision.
According to the invention, a display is provided in the driver""s field of vision. The display compares a value proportional to the maximum possible braking force with a value proportional to the actual braking force.
A value proportional to the braking force, for example, is the braking force itself, the deceleration resulting therefrom, or the stopping distance resulting therefrom. The maximum possible braking force and/or the value proportional to the maximum possible braking force can be determined and displayed variably as a function of driving parameters.
The comparative display can be in the form of numerical values, percentages, or bars for example.
In addition, a supplementary optical or acoustic signal can be produced when the value proportional to the actual braking force is equal to the value proportional to the maximum possible braking force.
However, the comparative display can also be presented in the form of a single item of information that expresses, for example, a difference or a percentage that indicates how close the value proportional to the actual braking force is to the value proportional to the maximum possible braking force. For example, if proximity sensors for determining the proximity of the vehicle to the vehicle ahead are provided in the vehicle, a display can be provided that compares the stopping distance resulting from the braking force existing at the moment with the maximum permissible braking distance to prevent a rear-end collision.
One advantageous improvement on the invention variably determines the value proportional to the maximum possible braking force as a function of a tire-road coefficient of friction instantaneously determined.
According to the invention, the value proportional to the maximum possible braking force is determined variably as a function of the tire-road coefficient of friction determined at the moment.
Various methods are already known for determining the tire-road coefficient of friction existing at the moment. For example, an additional display of this coefficient of friction could be provided.
The display device according to the invention prevents the driver from suspecting that the braking action is insufficient, especially at low coefficients of friction. In addition, when the value proportional to the actual braking force is smaller than the value proportional to the maximum possible braking force, the driver is informed that further deceleration is possible by increasing the braking force using the brake pedal.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.